Good ol' numerology, a favorite method of doomsday predictors. A "Christian conspiracy theorist" named David Meade claims he discovered that the world will end on Sept. 23 by combining Bible passages with astronomy — chiefly, the total solar eclipse over the U.S. in August. "Jesus lived for 33 years. The name Elohim, which is the name of God to the Jews, was mentioned 33 times [in the Bible]," Meade explained to The Washington Post. And Sept. 23 will mark 33 days since the eclipse. Voila!

Sounds iffy. Are there other signs?

You bet! A "code" in the pyramids points to Sept. 23 as well (it's unclear how, exactly). The Book of Revelation also supposedly points to Sept. 23 as the beginning of the end because it is a day when a number of celestial bodies — including the sun, moon, and constellations of Virgo and Leo — all line up. "The alignment in question will actually happen," National Geographic writes. "But the significance of the astronomy is debatable. The Biblical sign depends on the number of stars in play, and even astronomers don't agree how many stars officially make up Leo." Plus, this alignment happens for a couple days every September and October.

How exactly is the world supposed to end on Sept. 23?

There are a few different opinions on how we might greet oblivion. One is simply that Sept. 23 marks the day the Rapture will begin. Another says that a mysterious planet called Nibiru, also known as "Planet X," is going to crash into the Earth, The Sun reports. Meade claims that the solar eclipse marked the moment when Nibiru entered our solar system, and we've been rapidly approaching the end of the world ever since.

The rigor and reliability of Meade's "calculations," however, are not without their flaws. He originally thought Nibiru was going to collide with Earth in October, but then moved the date up to Sept. 23. In fact, people have been talking about Nibiru long before Meade set Sept. 23 as Earth's expiration date — Planet X was also supposed to collide with Earth in 2003 (a miscalculation, presumably).

For its part, NASA maintains that there is no such thing as Planet Nibiru. Then again, NASA probably doesn't even believe in the Anunnaki either.

What is an Anunnaki?

Anunnaki are ancient space aliens that created the human race, as Zecharia Sitchin describes in his book The 12th Planet, The Sun reports. Oh, and the Anunnaki live on Planet Nibiru.

Professor Anthony Aveni of Colgate University told National Geographic that Sept. 23 doomsaying is just another example of people searching for a narrative rather than accepting the randomness of the world and universe at large. "Everybody wants to know the chemical composition of the burning bush, or where exactly is the Ark of the Covenant," he said. "We want the final story, the bottom line."

NASA senior scientist David Morrison has a whole list of reasons why Nibiru (which doesn't exist) isn't poised to collide with Earth — namely that you'd be able to see it by now if it was. "If Nibiru were real and it were a planet with a substantial mass, then it would already be perturbing the orbits of Mars and Earth," he told The Washington Post.